at the bottom of your post there's a section "additional options" click on the tab for "manage attachments" and it will open a window where you can browes your computer files for the pic(s) you want. There is a 147 kb size limit on the pics so if you take them with a high resolution digital cam you may have to resize them before you try to attach them. Hope that helps.
You can also create an account at the Photobucket site and create folders and copy pics from there pretty easy.